Shiver all over, though not cold -- Tremble with fear

During the reign of Emperor Wudi of the Western Han Dynasty (206BC-AD8), there was a man named Yi Zong. Due to the emperor's mother's special kindness Yi was made county magistrate of the Shangdang Prefecture. After taking up the post, Yi did very well in managing the official business. He was both courageous and resolute in handling cases and administered punishments according to law for all persecutors equally, regardless of status or rank.

When Prince Xiucheng's son broke the law (Prince Xiucheng was the emperor's sister's son) Yi handled the case impartially, which pleased the emperor. Yi was transferred to serve as commander of the armed forces in the Henei Prefecture. As soon as he took office, Yi had all the members of a wealthy and influential family that brought calamities on the people in the area executed. For some time public order and the general mood of the Henei Prefecture society were greatly improved. If someone had lost something on the road, for example, nobody would pick it up and claim it as his own. When Yi became prefect of the Nanyang Prefecture he came to know Ning Cheng, a despotic landlord who pretended to be modest and courteous towards Yi. Soon after he assumed office in Nanyang, Yi conducted some investigations that revealed Ning's crimes and put in prison.

Later, Emperor Wudi appointed Yi prefect of Dingxiang Prefecture. At the time, public order in Dingxiang was very chaotic and when Yi took office there were 200 convicts in prison and more than 200 people offering bribes to absolve them. Yi treated the matter severely. He arrested the latter and punished them accordingly. More than 400 convicts were executed in a day.

From that day on, whenever Yi's name was mentioned, people in Dingxiang would tremble with fear 　 "they would shiver all over, though not cold.

The idiom   is used to refer to the state of extreme fear.